1. Field of the Invention
The invention relates generally to finFET structures. More particularly, the invention relates to finFET structures with enhanced performance.
2. Description of the Related Art
Semiconductor structures include both passive semiconductor devices such as resistors and capacitors, as well as active devices such as transistors and diodes. Field effect transistor devices are common transistor devices within semiconductor structures. Field effect transistor devices are often fabricated in complementary pairs to provide complementary metal oxide semiconductor (CMOS) structures. CMOS structures and CMOS devices are desirable insofar as CMOS structures and CMOS devices generally consume less power than other transistor structures and transistor devices.
Field effect transistor structure and device dimensions have been scaled effectively to increasingly smaller dimensions over the period of several decades. While such scaling is projected to continue, nonetheless field effect transistor performance improvements as a function of field effect transistor scaling are becoming more difficult to achieve. To that end, materials of construction of field effect transistors are now often routinely selected and controlled in an effort to provide additional avenues to enhance field effect transistor performance.
Various field effect transistor structures having desirable properties, including in particular CMOS structures, are known in the semiconductor fabrication art.
For example, Lee et al., in U.S. Pat. No. 6,653,698, teaches a CMOS structure that provides individual n-FET and p-FET devices having individual work functions. To realize such a CMOS structure, the individual n-FET and p-FET gate electrodes are fabricated at least in part from different metal gate materials.
In addition, Polischuk et al., in U.S. Pat. No. 6,794,234, also teaches a CMOS structure that provides individual n-FET and p-FET devices having individual work functions. To realize such as CMOS structure, the individual n-FET and p-FET gate electrodes are fabricated at least in part from different interdiffused metal gate materials.
Semiconductor device and semiconductor structure dimensions are certain to continue to decrease as semiconductor technology advances. Thus, desirable are novel semiconductor devices and semiconductor structures, including in particular CMOS devices and CMOS structures, that provide for enhanced performance.